HCPCS Code M0300: IV chelation therapy (chemical endarterectomy)

Key takeaways

HCPCS Code M0300 describes IV chelation therapy (chemical endarterectomy), the HCPCS Level II code for intravenous infusion of chelating agents such as EDTA.

Medicare covers M0300 for heavy metal poisoning with laboratory evidence, and treats chelation for atherosclerosis as experimental and non-covered.

Documentation errors are the top denial driver, so every M0300 claim needs a physician order, lab evidence of toxicity, and a written treatment rationale.

A non-covered indication still gets billed, with the GY modifier and a signed ABN, because the denial record is what makes the patient billable.

Practice management software like Pabau tracks payer-specific coverage rules and flags incomplete documentation before claims reach the clearinghouse.

HCPCS Code M0300 is the HCPCS Level II code for IV chelation therapy, also described as chemical endarterectomy. It covers the intravenous infusion of chelating agents, primarily ethylene diamine tetraacetic acid (EDTA).

Coverage splits on the indication behind the infusion. Medicare and the major commercial payers pay M0300 for heavy metal poisoning backed by lab evidence, and deny it for atherosclerosis. This reference covers the 2026 fee schedule position, payer policies, ICD-10 pairings, crosswalk codes, and the documentation each path needs.

HCPCS Code M0300: Definition and key attributes

M0300 sits in the Miscellaneous Medical Services group of HCPCS Level II. It covers administration of a chelating agent, primarily EDTA, given to bind and remove heavy metals. The same code carries the off-label cardiovascular use, where chelation is given to treat atherosclerosis.

The Centers for Medicare and Medicaid Services (CMS) maintains HCPCS Level II codes and issues quarterly updates. M0300 has remained active through the most recent quarterly release and carries no termination date for the 2026 coding year.

What is IV chelation therapy (chemical endarterectomy)?

IV chelation therapy is the intravenous infusion of a chelating agent, most commonly EDTA, that binds heavy metal ions in the bloodstream.

Once bound, the metal-chelate complex leaves the body through the kidneys. The term “chemical endarterectomy” reflects the historical cardiovascular use, where proponents argued that chelation could clear arterial plaques.

Two distinct patient populations receive this treatment, and the billing path differs sharply between them. Practices offering chelation in integrative or functional medicine settings see mostly the second and third groups below.

• Heavy metal poisoning (covered indication): Patients with confirmed lead, mercury, arsenic, or other heavy metal toxicity, documented by laboratory blood or urine testing. EDTA is FDA-approved for lead poisoning and is medically necessary when lab values meet clinical thresholds.
• Cardiovascular or atherosclerosis (non-covered indication): Chelation given to treat or prevent cardiovascular disease. Major payers, including Medicare, Aetna, and Blue Cross Blue Shield, classify this use as experimental and investigational. Coverage is routinely denied.
• Integrative medicine protocols: Some practices bill chelation as part of a broader wellness or detoxification program. These claims meet the same non-coverage determination as cardiovascular indications, unless lab evidence of heavy metal toxicity supports them.

2026 fee schedule rates and payment status

Medicare fee schedule rates for M0300 vary by locality and carrier. Because Medicare treats chelation for cardiovascular indications as non-covered, the published rate in most localities reflects that status rather than a payable amount.

For the covered heavy metal poisoning indication, check the current rate in the CMS Physician Fee Schedule lookup tool. Rates differ between facility and non-facility settings and change annually.

For practices billing commercial insurance, the contracted rate and the coverage determination both sit in the plan’s own medical policy bulletin. Confirm reimbursement eligibility before administering the infusion.

Medicare and commercial payer coverage

Coverage for M0300 is payer-specific and indication-driven. Medicare states plainly that chelation therapy for atherosclerosis or cardiovascular disease is non-covered, and most major commercial payers hold the same position.

Before billing M0300, confirm the coverage status with the specific payer and plan. Some payers also require physician supervision of the infusion, so record the credentials of whoever administered it. Auditors ask for proof of provider qualifications more often on chelation claims than on routine infusions.

Covered vs non-covered indications

When billing a Medicare patient for a non-covered indication, issue an Advance Beneficiary Notice of Non-coverage (ABN) before administering the service.

Without a valid ABN, the practice cannot collect from the patient once Medicare denies the claim. The diagnosis code, the modifier, and the consent step all follow from that same lab result.

ICD-10 diagnosis codes used with M0300

Pairing M0300 with the correct ICD-10 diagnosis code decides whether a claim is approved or denied. The applicable codes depend entirely on the clinical indication. Only use diagnosis codes that the patient’s record and laboratory findings support.

The T56 and T57 series codes for toxic effects of metals are the most commonly paired diagnoses on covered M0300 claims. Always use the most specific code available, including the seventh character for encounter type. That character is A for an initial encounter, D for a subsequent one, and S for sequela.

Full descriptions for each of these codes sit in the ICD-10-CM code index, and the AAPC HCPCS code lookup cross-references them against current payer policies.

Related and crosswalk codes

M0300 rarely travels alone on a claim. Several CPT and HCPCS codes are billed alongside it, or take its place, depending on how the service is structured.

For the infusion administration itself, bill CPT 96365 for the first hour and CPT 96366 for each additional hour. Some payers will not reimburse M0300 separately if they treat it as bundled into those administration codes. Confirm the bundling rules with the MAC or the commercial payer before submitting.

M0300 billing guidelines and documentation requirements

Clean M0300 claims have their documentation assembled before the infusion begins, not after the denial. The checklist below is what a payer or auditor asks for on a chelation claim, and the order in which the record should carry it.

Documentation checklist

• Laboratory evidence: Blood or urine metal concentration results showing levels consistent with toxicity, such as a blood lead level above the CDC reference value. The result must be dated within a clinically relevant window before treatment.
• Physician order: A signed order specifying the chelating agent, dose, route, and frequency. The ordering provider’s NPI must appear on the claim.
• Diagnosis documentation: The treating diagnosis in the clinical note must match the ICD-10 code on the claim. Vague wording such as “heavy metal exposure” is insufficient without lab confirmation.
• Treatment rationale: A clinical note explaining why IV chelation is medically necessary for this patient now, referencing the lab values and the clinical presentation.
• Infusion log: Start and stop times, agent administered, dose, lot number where applicable, adverse event monitoring, and staff credentials. A structured intake and infusion record keeps all of it in one place at audit.
• ABN where applicable: For a Medicare patient receiving chelation for a non-covered indication, a completed ABN signed before service delivery is mandatory.

Prior authorization and claim submission tips

Prior authorization requirements vary by payer. Most commercial plans that cover M0300 for heavy metal poisoning require it, particularly for a multi-session course. Check the payer’s provider portal or call the authorization line before scheduling the first infusion.

• Submit the lab evidence with the authorization request, not just the clinical note. Reviewers at commercial payers need the values themselves, not a summary.
• For Medicare claims carrying the GY modifier, expect no reimbursement. The submission creates the denial record that satisfies the ABN requirement and lets you bill the patient.
• If a claim is denied for medical necessity, appeal with the physician’s clinical rationale alongside the lab documentation. Assemble that packet before the first submission rather than after the denial letter arrives.
• For multi-session courses, confirm whether the payer requires re-authorization after a set number of sessions. Some plans cap chelation at a defined number of infusions per calendar year.

M0300 code history and status updates

CMS issues HCPCS code updates quarterly. M0300 has been an active code for several years. The October 2025 quarterly update published by CGS Medicare (Jurisdiction C) confirmed it as active. No revision or deletion action was taken on M0300 in that update cycle.

Check the code status against the CMS annual HCPCS update file before you bill, and again after each quarterly release. A quarterly update can change a code’s status, its description, or the coverage notes attached to it.

How Pabau simplifies M0300 billing

Most practices billing chelation keep the pieces of an M0300 claim in separate places. Lab results arrive by fax or portal. The physician order sits in the chart and the ABN goes in a paper folder. The coder then assembles all three at submission. A missing lab result is only discovered when the denial posts, weeks later.

Practice management software like Pabau keeps the payer rules and the record in the same system. Pabau’s claims management software checks each claim against payer-specific rules before it goes out. It flags the missing lab evidence or physician order that M0300 claims consistently need. Intake, consent, lab results, and the infusion note live on one patient record, so an audit request is answered from one screen.

The result is a shorter path from infusion to payment. Coverage rules get applied before the appointment rather than after the denial, so your team spends its time on the appeals worth filing.

Stop chelation claims from stalling in denials

Pabau tracks payer-specific coverage rules and flags incomplete documentation before M0300 claims reach the clearinghouse. See how integrated billing keeps infusion revenue moving.

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Conclusion

M0300 pays on one condition, and that condition is a lab result. Practices that collect on chelation decide the billing path at booking. At that point there is still time to order the test, write the rationale, or get the ABN signed. Deciding it at submission means the claim is already coded wrong.

The trade-off worth remembering is that a non-covered chelation claim is still worth submitting. The GY modifier turns a denial into the record that makes the patient billable, so the revenue survives even where coverage does not. Book a demo to see how Pabau applies payer coverage rules to infusion claims before they leave your practice.

Continue your research

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